The specific aim of this core is to provide essential imaging support for projects in the grant. In addition to continuing the use of ultrasound to diagnose autosomal dominant polycystic kidney disease (ADPKD), ultrasound will be used to assess the natural history of ADPKD by longitudinally imaging patients. Liver and kidney volume, percentage of normal parenchyma, and percentage of cyst involvement will be measured. Selected pregnant patients will be imaged to determine earliest manifestation of ADPKD in utero and the fetuses will be evaluated for renal size, echogenicity, and presence or absence of renal cysts. Growth of the fetal liver and fetal kidneys will also be monitored. Extrarenal manifestations of the disease will be evaluated. Intracranial aneurysms will be evaluated primarily by dynamic computed tomography with angiography for confirmation of suspicious lesions. Certain ADPKD patients will be evaluated for diverticula by air-contrast barium enema.